The video later shows a shirtless man in a while baseball cap approaching the man in custody and apparently taunting him.

Kimberly Couzens, 25, who lives on the Upper East Side, said she was in the park reading Thursday when she noticed a parks vehicle zooming through the middle of the square in the heat.

She said she heard from some eyewitnesses that two men had been stabbed and that there had been a chase as police tried to apprehend the perp.

"I can’t believe it," said Couzens after learning the details of the alleged attack. "It's scary to think someone might up and stab you while you're relaxing in the park."

Fox News Channel correspondent Laura Ingle was also in the park during the alleged stabbing.

"Nothing like a stabbing to interrupt a day of doing live shots at George Washington Square park," she tweeted, along with an image of the man in the video pinned against the back of a police car while apparently being searched by police.

Graham was arrested on two counts of assault and one court of criminal possession of a weapon, police said.

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